1. Field of the Invention
The subject invention relates to centrifugal fan assemblies.
2. Description of the Prior Art
In the prior art, numerous centrifugal fan assemblies are disclosed for drawing air axially into the center and throwing the air radially. Such centrifugal fan assemblies include a housing having a lower surface and an inlet wall defining an inlet opening and a shaft supported by the housing for rotating about an axis aligned with the inlet opening. A plurality of fan blades are disposed about the shaft and extend radially from the axis for drawing air axially into the blades and for blowing air radially outwardly. The housing defines a scroll wall spiraling about the axis to an outlet air passage that extends substantially tangentially to the axis. An example of a centrifugal fan assembly is shown in U.S. Pat. No. 6,893,220, issued to Eaton et al.
Some centrifugal fan assemblies can produce objectionable noise and do not obtain sufficient efficiency.